X-KAY IMICHOSCOI'Y 



contradict the view generally accepted that the latter are calcified and the former not. 



the growth of long tubular bones in length is Serial microradiographs demonstrate also 



not affected in this disease. Their micro- fibers partiall}^ or completely decalcified, 



radiographs demonstrate clearly pathological From these obser\ations we suggest that the 



changes in epiphysial plates and metaphyses. decalcification of l)one fibers and not their 



We would like to emphasize especially the destruction is the characteristic sign of aging 



important work of Italian scientists in the bone atrophy. In other words, the old 



field of bone microradiography. Orlandini halisteresis theory is revived by stain histo- 



et al. (94), using microradiography as the radiographical findings (Fig. 12). 



main method, investigated formation and It is proposed in the same work to differ- 



evolution of callus of bone fractures, the entiate between osteoporosis and bone 



changes in ear ossicles in the course of atrophy using the first term only in case of 



chronic inflammation of the middle ear, the pathological destruction of bone, 



bone changes in osteomyelitis, leukemia, etc. As mentioned above, the physicochemical 



Starcich (108) proposed a new classification approach is also possible in the study of 



of myelomatous osteopathies based on his "white" microradiographs of calcium-con- 



microradiographical observations. Prevedi taining tissues and is effected by comparing 



and Margato (96) investigated the growth of x-ray absorption (1) of a standard wedge of 



bone. The main purpose of all the above which the thickness is increased step-wise, 



work was to show the importance of micro- and (2) of the desired part of the specimen, 



radiography in bone research, and this pur- Aluminum or collodion are used as material 



pose was excellently achieved. for wedges in this research. The Laboratory 



Microradiographic studies of resorptive for Morphological Ultra Structural Research 



processes in bone were initiated by Lacroix in Geneva uses this method (Baud) (10). The 



and Ponlot (79) with their work on post- reference system of Engstrom and Lind- 



traumatic osteoporosis, in w^hich this method strom may also be used for this analysis 



was used parallel with autoradiography and (Amprino and Engstrom) (117). We are of 



histology. This work demonstrated the im- the opinion, however, that change of bone 



portance of comparing microradiographs and density alone without some accompanying 



histological preparations of the same speci- morphological changes cannot be accepted 



men: large areas of the calcium -free fibrous as a decisive diagnostic sign, especially in 



tissue w^ere found in histological specimens cases of bone atrophy, because individual 



within the atrophic osteon. The same ob- variations are very great, 



servation was made by Bohatirchuk in his This quantitative approach to the deter- 



works on aging bone atrophy (27) (28) (29) mination of the calcium content via micro- 



(12G) (127) (128). Decalcified bone tissue was radiography is especially well worked out in 



found by him everywhere in aging atrophic dental research. Even in 1936 Hollander (76) 



bone. According to the Albright-Pommer described an original x-ray microdensitome- 



theory (1), this decalcified tissue is a new ter for qualitative analysis of teeth calcium, 



matrix produced by osteoblasts, and this The effective intensities were measured by a 



matrix onl}^ failed to calcify. The same double ionization camera after x-rays passed 



theory considers the complete destruction through the desired part of the tooth and 



of the old matrix to be the prerequisite of through the standard wedge of aluminum, 



any bone atrophy. However, stain histo- The author considered the possible error to 



radiographs reveal that fibers of atrophic be only 0.3%. He worked Avith tooth speci- 



tissue are the exact continuation of bone mens 300 m thick and with x-rays obtained 



collagen fibers; the only difference is that at 18 kv. 



610 



